Polymethine dyes



United States PatentO "i 7. 2,705,234

1 2 2 705 234 The compounds of general Formula III are also valuable sensitisers for photographic silver halide emul- POLYMETHINE DYES sions and particularly photographic gelatino silver John David Kendall and Douglas James Fry, Ilford, Engbromide emulsions- Patented Mar. 29, 1955..-

land, assignors to -Ilford Limited, Ilford, England, a According to a further aspect of the present invention, Bl'ltlsh company a further new class of cyanine dyestulf is obtained by. No Drawing. Application February 25, 1952 treating a compound of the general Formula III with a S ri l N 273,344 compound of the general formula R5X which is capable of forming a quaternary salt with an amine, R5 being an Clams pnonty apphcanon Great Bntam March 51951 alkyl or aralkyl radicle and X being the anion of a strong 6 Claims. (Cl. 260-2405) acid. Typical compounds R5X which may be employed This invention relates to polymethine dyestufis 1n th1s aspect of the mvennon are methyl and ethyl 1od1des In application Serial No. 214,016, filed March 5, 1951, and p-toluene sulphonates and B+ y y y bromide. now U. S. Patent No. 2,637,729, issued May 5, 1953, The products have the general Formula IV:

|'D1--1 F' D,2""-"""] I\'I CHCH)..=(' (CH=0H-).CH=0-(CH=CH-),oH=(CH=oH ,,,-1 I R; X R; (N there is described a process for the production of cyanine and, like the parent compounds, are valuable sensitisers dyes which comprises heatmg with a prlmary alkylamine for photographic silver halide emulsions. (including cycloalkylamine), aralkylamine or arylamine The following examples will serve to illustrate the a compound of the general Formula I: invention. The new compoundslof Formula III have |-'-D1-'-'] SR2 r- D-'-- I I= cH-cH ..=('J- GH=CH-).CH=(b(CH=CH-),oH=(':- oH=cH 1iI R1 X R] (1) where R1 and R3 are the same or different and each been named as hydrocarbons terminally-substituted by represents an alkyl, hydroxyalkyl or aralkyl group, R2 dihydro heterocyclic radicles linked by double bonds represents an alkyl or aralkyl group, D1 and D2 are the to the hydrocarbon chain and with an imino substituent same or different and each represents the residue of a in the chain. five-membered or six-membered heterocyclic ring system EXAMPLE 1 of the type known for use in cyanine dyes, X represents an acid radicle, and n, m, x and y are the same or 1.3-b1s-(3-methyl 2.3 dzhydrobenzthzazolyhdene)-2- different and each represents nought or one. (phenylimino) propane Preferably R1 and R3 represent lower alkyl groups, 40. 3:3'-dirnethyl-9-anilinothiacarbocyanine,bromide (4 g.) e. g. methyl, alkyl, propyl or butyl, or corresponding was suspended in warm methanol (200 'cc.) and stirred hydroxyalkyl groups, and R2 also represents a lower alkyl while 2 /2 sodium hydroxide solution (40 cc.) was group, e. g. methyl, ethyl, propyl or butyl. added; the colour changed from red to yellow. The

D1 and D2 may each be the residue of any of the mixture was diluted with water and the precipitated types of heterocyclic nuclei commonly employedinphoto-- product filtered off. After drying, it was purified by graphic sensitising dyes, e. g. thiazoles, oxazoles, selenaextracting in a Soxhlet extractor with ether. The ether zoles and their polycyclic homologues such as those of solution was concentrated when the product separated the benzene, naphthalene, acenaphthene and anthracene as orange-yellow crystals, in. pt. 197 C. Incorporated series; pyridine and its polycyclic homologues such as in a gelatino-silver iodobromide {emulsion it extended quinolme and a. and 5. naphthaqumolines; lep dines III- the Sensitivity to 6600 A with a maximum at 5950 A dolenines; diazlnes such as pyr1m1d1nes and qumazollnes; 3

diazoles (e. g. thio-ti flil'-diazlone)i oxazolines,dthiafzolgnes EXAMPLE 2;"

and selenazolines. T e p0 ycycic compoun s o t ese series may be substituted in the carbocyclic rings by one gi g 52 5 35 22;figggzgffgfg zgf fizigg' 3 2; or more groups such as alkyl, aryl, amino, hydroxy, al- 55 y y p y P P,

koxy andmethylenedioxy groups or by halogen atoms. 3-methyl-3-ethyl-9-anilinothiacarbocyanine iodide (10 The acid radicle X may be, for example, a halide g.) was mixed with a solution of sodium (2.3 g.) in methradicle (chloride, bromide or iodide), alkyl sulphate or anol (200 cc.) and the mixture heated on a water-bath for p-toluene sulphonate. 30 minutes. The yellow product was filtered oflf after The basic reagent employed may be aniline or another cooling, and washed with cold methanol. It was purified, primary aliphatic or aromatic amine. by extraction in a Soxhlet extractor with ether, from- The products have the general Formula II: which it separated as yellow fluffy crystals, in. pt. l72

r"-'D1-'-- r--D2--' 1 I= orr-o11 on=oH- .oH=ocH=oH- ,orr= o11=o11 1ir R1 X RI (II) where R4 is an alkyl, cycloalkyl, aralkyl or aryl radicle 173 C. Incorporated in a gelatino-silver iodobromide and the other symbols have the meanings assigned to 'emulsion it extended the sensitivity to 6200 A. with a them above.

According to the present invention further cyanine maximum at 5950 dyes of related structure may be obtained by treating a EXAMPLE 3 dyestufi of the Formula II with a strong base. Preferably a strong inorganic base is employed, such as an alkali hydroxide, but strong organic bases such as sodium 75 ethoxide or other alkali alkoxides may also. be employed.

-' 1-(3-methyl 2:3 dihydrobenzthiazolylidene) 3 3- ethyl-Z:3-dihydrobenzthiazolylidene) 2 (4 ethoxyphenylimino) propane The efiect of the treatment is to remove the elements 3-methyl-3'-ethyl-Q-phenetidinothiacarbocyanine iodide HX from the compounds so that they conform to the (5 g.) was ground in a mortar w1th acetone and 10% general Formula III: I sodium hydroxide solution (5 cc.); thered dye changed ,----D1----, NR1 -----D1---- to an orange-yellow solid. The paste was diluted with water (120 cc.) and the product collected by filtration and 5800 5..

EXAMPLE 4 3 methyl 3' ethyl-9-(methylphenylamfno)thiacarbocyanine iodide 1-(3-methyl-2:3-dihydrobenzthiazolylidene) 3 (3- ethyl 2:3 dihydrobenzthiazolylidene)-2- (phenylimino) propane (2.5 g.) was boiled with methyl iodide (20 cc.) for 10 hours; a magenta colour developed. The solution was diluted with ether (500 cc.) and the precipitated dye collected. It crystallised from methanol (100 cc.) as green prisms, m. pt. 167169 C.

The same compound was obtained when the starting material (2.5 g.) was heated at 100 C. for hours with methyl p-toluene sulphonate (5 g.). The magenta melt was dissolved in methanol and the dye precipitated as the iodide by treatment with aqueous potassium iodide; the dye obtained was recrystallised from methanol giving green prisms, rn. pt. 167-169 C. Incorporated in a gelatino-silver iodobromide emulsion it extended the sensitivity to 6400 A. with a maximum at 6150 A.

EXAMPLE 5 3 methyl 3' ethyl 9-(ethylphenylamin0) thiacarbocyanine iodide The reaction described under Example 4 was repeated using ethyl iodide (20 cc.) in place of methyl iodide. The crude dye crystallised from aqueous alcohol as fine maroon crystals, m. pt. l63l65 C. (with decomposition). Incorporated in a silver iodobromide emulsion it extended the sensitivity to 6300 A. with a maximum at EXAMPLE 6 3 methyl 3' ethyl 9 (4 ethoxyphenylmethyl amino)thiacarb0cyanine perchlorate l (3 methyl 2:3 dihydrobenzthiazolylidene) 3- (3 ethyl 2:3 dihydrobenzthiazolylidene) 2 (4- ethoxyphenylimino) propane (2.5 g.) was heated on the water-bath for 10 hours with methyl iodide cc.) The red solution was diluted with ether (200 cc.) and the precipitated crude product was converted to the perchlorate with aqueous sodium perchlorate. The perchlorate was purified by dissolution in ethanol (50 cc.) and precipitation with water (200 cc.) when it separated as fine red crystals, m. pt. 148 C.

EXAMPLE 7 I (3 methyldihydrobenzthiazolylidene) 3 (3 ethyldihydrobenzthiazolylidene)-2-eycl0hexylimin0pr0pane 0.54 gm. of 3'ethyl- '-methyl-9-cyclohexylaminothiacarbocyanine iodide was mixed with 20 mls. of methyl alcohol and 0.108 gm. of sodium hydroxide added, followed by 30 mls. of water. The mixture was extracted with ether, the extract dried with anhydrous sodium sulphate and evaporated in a vacuum desiccator. The residue was extracted in a Soxhlet extractor with dry ether, from which the product was obtained as a cream-coloured powder, m. pt. 169-171" C. When the dye was incorporated in a silver chlorobromide emulsion the sensitivity was extended to 5600 A. with a maximum at 4900 A.

EXAMPLE 8 I (3 methyldihydrobenzthiazolylidene) 3 (3- ethyldihydrobenzthiazoly lidene) -2-m ethylim inopropane 0.93 gm. of 3-ethyl-3'-methyI-Q-methylanfinothiacarbocyanine iodide was shaken with a mixture of 5 mls. of methyl alcohol and 5 mls. of normal sodium hydroxide solution. The mixture was extracted with ether, the extract dried with sodium sulphate and evaporated in vacuo. The product was obtained as an orange solid, in. pt. 134-137" C. When the dye was incorporated in a silver chlorobromide emulsion the sensitivity was extended to 5400 A. with a maximum at 4950 A.

EXAMPLE 9 1 (3 methyldihydrobenzoxhzolylidene) 3 (3 ethyldihydrobenzthiazolylidene) -2-p-t0lylimin0pr0pane with a maximum at 4950 A.

EXAMPLE 10 1 (1:3:3 trimethylindolinylidene) 5 (3 methyldihya'robenzthiazolylidene) 4 p-ethoxyphenylimina-Z- pentene 0.3 gm. of l:3:3:3-tetramethyl-1l-p-phenetidinoindothiadicarbocyanine iodide was dissolved in 10 mls. of spirit and a solution of 0.04 gm. of sodium in 2 mls. of ethyl alcohol added. The mixture was diluted with 20 mls. of water, the solid filtered off, dried and extracted in a Soxhlet extractor with ether. The product separated from the ether as yellow needles, m. pt. 199201 C. When the dye was incorporated in a silver iodobromide emulsion the sensitivity was extended to 6600 A. with a maximum at 6200 A.

EXAMPLE 11 1 (1 methyldihydroquinolylidene(2) 3 (3 ethyldihydrobenzthiazolylidene) -2-p-tolyliminopropane 0.30 gm. of 3-ethyl-l'-methyl-9-p-toluidinothiaquino- Z-carbocyanine perchlorate was dissolved in 20 mls. of ethyl alcohol and a solution of 0.046 gm. of sodium in ethyl alcohol added. The mixture was stirred and diluted with water. The solid was filtered ofi, dried and extracted with ether. By concentration of the ether extracts the product was obtained as purple crystals, 111. pt. 2l0-2l4 C. When the dye was incorporated in a silver iodobromide emulsion the sensitivity was extended to 6400 A. with a maximum at 5700 A.

EXAMPLE 12 1 (I methyldihydroquinolylia'ene(2)) -3 (3 methyldihydrobenzthiazolylidene)-2-p-tolyliminopr0pane 0.22 gm. of 3:l'-dimethyl-9-p-toluidinothiaquino-2- carbocyanine iodide was dissolved in 10 mls. of hot ethyl alcohol and an alcoholic solution of 0.046 gm. of sodium added. After dilution with water, the solid was filtered otf, dried and extracted with ether. Concentration of the ether extracts gave the product as brownish-yellow crystals, m. pt. 220-228 C.

EXAMPLE 13 3 methyl 3' ethyl 9 methylahilinothiacarbocyaninc iodide 0.25 gm. of l-(3-methyldihydrobenzthiazolylidene)- 3 (3 ethyldlhydrobenzthiazolylidene)-2-phenyliminopropane was fused at 100 C. for 5% hours with 0.5 gm. of methyl toluene-p-sulphonate. The melt was dissolved m 4.5 mls. of methyl alcohol and poured into a warm solution of potassium iodide. The dye was filtered off and crystallised in 10 mls. of methyl alcohol, from which it separated as green crystals, m. pt. 167-169 C.

EXAMPLE l4 3 methyl 3' ethyl 9 methylcyclohexylaminothiacarbocyanine iodide 0.18 gm. of l-(3-methyldihydrobenzthiazolylidene)-3- a (3 ethyl dihydrobenzthiazolylidene) 2 cyclohexyliminopropane was heated under reflux with 10 mls. of freshly distilled methyl iodide for 7 /2 hours. After dilution with ether the dye was filtered oif and purified by dissolving in a mixture of hot ethyl alcohol and ethyl acetate. A little solid which separated on cooling was discarded. Addition of ether to the filtrate precipitated the dye as an orange powder, m. pt. l163 C. When the dye was incorporated in a silver chlorobromide emulsion the sensitivity was extended to 5450 mum at 4900 A.

with a maxi- EXAMPLE l 3 methyl 3 ethyl 9 dimethylaminothiacarbocyanine perchlorate 0.13 gm. of 1-(3-methyldihydrobenzthiazolylidene)-3- (3 ethyl dihydrobenzthiazolylidene) 2 methyliminopropane was heated with methyl iodide for 1% hours. The product was precipitated by adding ether, filtered ofi, re-dissolved in spirit and the solution poured into aqueous potassium perchlorate solution. The dye was filtered oi). and purified by dissolving in 10 mls. of ethyl alcohol and precipitated by adding ether, when it was obtained as an orange powder, m. pt. 135-140 C. When the dye was incorporated in a silver chlorobromide emulsion the sensitivity was extended to 5350 A. with a maximum at 4900 A.

EXAMPLE 16 3-methyl-3'-ethyl-9-methylethylamin0thiacarbocyanine perchlorate extended to 5300 A. with a maximum at 4900 A.

EXAMPLE 17 3-methyl-3'-ethyl-9-methylbenzylaminothiacarbocyanine perchlorate 0.20 gm. of 1-(3-methyldihydrobenzthiazolylidene) 3 (3 ethyl-dihydrobenzthiazolylidene)-2-methyliminopropane was heated for 12 hour with 2 mls. of benzyl bromide. After dilution with ether the dye was filtered off, re-dissolved in alcohol and poured into aqueous sodium perchlorate. The product was filtered oflf and crystallised from 17% mls. of ethyl alcohol as orange crystals, m. pt. 134-136 C. When the dye was incorporated in a silver chlorobromide en 1l1lsion the sensitivity was extended to 5300 A. with a maximum at 4900 A.

EXAMPLE 1s 3-methyl-3'-ethyl-9-methyl-p-toluidino-oxathiacarbocyam'ne perchlorate 0.18 gm. of 1-(3-methyldihydrobenzoxazolylidene)-3- 5 obtained had m. pt. 142l46 C.

.. 6 sensitivity was extended to 5650 A. with a broad maximum at 5100 A.

EXAMPLE 19 1 :3:3:3'-tetramethyl-1 1 -methyl-p-ph enetidino-indoth iacarboeyanine iodide 0.08 gm. of l-(l:3:3-trimethylindolinylidene)-5-(3- 10 methyldihydrobenzthiazolylidene) 4-p-ethoxyphenylirni- EXAMPLE 20 3-ethyl-3'-methyl-9-methylanilin0thiacarbocyanine iodide 0.11 gm. of 3-ethy1-3'-methyl-9-anilinothiacarbocyanine iodide was mixed with a solution of 0.0051 gm. of sodium in 0.22 ml. of methyl alcohol. On adding 1 ml. of methyl iodide a yellow solution was formed which when heated became red. After heating for 9 hours the solution was diluted with ether and the product filtered olf. The crude dye was crystallised from 6 mls. of methyl alcohol to give green crystals, m. pt. 162 C.

Although many of the foregoing examples use only small quantities of the reagents, it is to be understood that larger quantities may be employed by the same processes to yield larger quantities of the dyestuffs described.

The present invention includes dyestutfs of general Formulae III and IV, processes for the production of such dyestuffs and photographic silver halide emulsions containing such dyestuifs in sensitising amount.

What we claim is:

1. Dyestuffs selected from the class consisting of dyestuffs of the general formula:

and quaternary salts thereof of the general formula:

where R1 and Rs are each selected from the class con- (3 ethyl-dihydrobenzthiazolylidene)-2-p-tolyliminopropane was heated with 2 mls. of methyl iodide for 1 /2 hours. After dilution with ether the dye was filtered oil, re-dissolved in ethyl alcohol and poured into aqueous sodium perchlorate. After two recrystallisations the orange-red product melted at 220-224 C. When the the general formula:

where R1 and Rs are each selected from the class consisting of alkyl, hydroxyalkyl and aralkyl groups, R4 is selected from the class consisting of alkyl, cycloalkyl, aralkyl and aryl radicles, D1 and D2 are each the residue of a dye was incorporated in a silver chloride emulsion the five-membered or six-membered heterocyclic nitrogen nucleus of the type used in cyanine dyes, X is a acid radicle, and n, x, y and m are each'selected from nought and one.

3. Process according to claim 2 wherein the strong base employed is an alkali hydroxide.

4. Process according to claim 2 wherein the strong base employed is an alkali alkoxide.

5. Process for the production of a dyestuff of the general formula:

which comprises subjecting to treatment with a compound RsX a compound of the general formula:

6. Process according to claim 5 wherein the compound Rex is an alkyl iodide.

References Cited in the file of this patent UNITED STATES PATENTS 2,166,736 White et a1 July 18, 1939 2,169,434 Schwarz Aug. 15, 1939 2,263,749 White et a1. Nov. 25, 1941 2,320,654 Riester June 1, 1943 2,322,015 Hamer et al June 15, 1943 2,338,782 Riester Ian. 11, 1944 2,340,882 Kendall Feb. 8, 1944 2,353,164 Kendall et al July 11, 1944 2,637,729 Kendall May 5, 1953 OTHER REFERENCES Chem. Abstracts 16:3101 (Abstract of Brit. Med. Jouri,

Chem. Abstracts 19:530 (Abstract of Proc. Roy. Soc.,

London, 96B, 317-333, 1924). 

1. DYESTUFFS SELECTED FROM THE CLASS CONSISTING OF DYESTUFFS OF THE GENERAL FORMULA: 